Ion flotation of cadmium using ethylhexadecyldimethylammonium bromide

Cadmium ions react with the collector, ethylhexadecyldimethylammonium bromide (EHDABr), to form a surface-active sublate which can be removed from aqueous bromide

a. Effect of Foreign Metal Ions on the Flotation of Cadmium^a

Foreign ion	Foreign ion concentration (M) (×10?5)	Foreign ion removed (%)	Cadmium removed (%)
None			99.21
Zn2+	6.11	0.06	98.41
Cu2+	6.29	3.64	97.80
Pb2+	3.86	4.80	91.78
Cr6+	7.69	30.75	99.07 solutions by ion flotation. A typical ion flotation procedure involves passing air through a 250-ml solution containing 5 ppm Cd2+, 0.05 M Br?1, and 1.7 × l0?3M EHDABr at a flow rate of 40 ml/min for 1 hr. The procedure was simple and efficient. Chromium, copper, and zinc ions do not interfere under the experimental conditions.

a

Cd²⁺, 4.46 × 10^?5M; EHDABr, 4.25 × 10^?4; Br^?, 5 × 10^?2M; flow rate, 40 ml/min; time, 60 min.

     

A new kinetic method for the determination of magnesium and its application to natural waters

A kinetic method is described for the determination of trace amounts of magnesium in the presence of calcium. The procedure is based on the inhibition of the manganese(II) catalyzed aerial oxidation of 1,4-dihydroxyphthalimide dithiosemicarbazone reaction by

2. Effect of Transition Metals^a

Transition metal	Concentration (M)	Percentage inhibition	Mg(II) found (×l05M)
Fe(II)	3.6.10?5	54.1	4.62
Fe(III)	3.6.10?5	47.8	4.48
Co(II)	3.4.10?5	50.0	4.53
Ni(II)	3.4.10?5	50.0	4.53
Cu(II)	3.1.10?5	52.0	4.56
Zn(II)	3.0.10?5	54.1	4.62
Cd(II)	1.7.10?5	52.0	4.56
Hg(II)	9.9.10?6	45.8	4.44
Sn(II)	2.1.10?6	50.0	4.52
Pb(II)	1.2.10?6	54.1	4.62

a

Conditions: 4.53.10^?5M Mg(II), 35 ng Mn ml^?1, 0.429 M ammonia, 1.6.10^?4M OH-PDT.

3. Determination of Magnesium in Natural Waters

			Mg(II) found (M)b
Natural water	Ca(II) presenta		Atomic absorption
sample	M	Kinetic absorption	method
Commercial	3.45 · 10?4	1.65 · 10?3	1.74 · 10?3
Commercial	5.46 · 10?4	1.57 · 10?4	1.81 · 10?4
Untreated	6.13 · 10?4	2.16 · 10?4	2.40 · 10?4
Treated	4.95 · 10?4	1.93 · 10?4	2.17 · 10?4

a

EDTA titration less the magnesium.

b

Average of three separate determinations. traces of magnesium(II). The reaction is followed spectrophotometrically by measuring the rate of change in absorbance at 594 nm. The calibration graph (percentage inhibition vs magnesium concentration) is linear in the range 329–535 · 10^?5M with an accuracy and precision of 1.2%. The method has been applied to the determination of magnesium in natural waters at low concentrations.

     

The vibrational ground state rotational spectroscopic constants and structure of the HCN dimer

Rotational spectra have been assigned for four isotopic species of the linear HCN dimer in the vibrational ground state. The spectroscopic constants are

     

4.

Spectrofluorimetric determination of thallium in silicate rocks with rhodamine b in the presence of aluminum chloride     

Marian M. Shnepfe 《Analytica chimica acta》1975

A sensitive spectrofluorimetric procedure with rhodamine B in the presence of aluminum chloride is given for determining submicrogram and microgram quantities of thallium in silicate rocks. Samples are decomposed with a mixture of hydrofluoric and nitric acids and then treated with hydrochloric acid. Thallium is extracted as its dithizonate with chloroform from an alkaline medium containing ascorbate, citrate, and cyanide and then back-extracted with dilute nitric acid. After destruction of the organic matter and treatment with bromine, hydrochloric acid, aluminum chloride, and rhodamine B, the

T001. Determination of thallium in U.S. Geological Survey standard rocks by different laboratories

isotope	-B0 (MHz)	DJ (kHz)	xN1 (MHz)	xN2 (MHz)
HC14N-HC14N	1745.80973(50)	2.133(30)	?4.0973(200)	?4.4400(190)
HC14N-HC15N	1700.30190(30)	1.939(40)	?4.1059(10)	-
HC15N-HC14N	1729.92082(20)	2.023(30)	-	?4.4339(6)
HC15N-HC15N	1684.28825(25)	1.900(30)	-	-

Thallium (p.p.m.)		Method	Ref.
G-1	W-1
1.06	0.102	Neutron activation analysis	1
1.08	0.121, 0.116	Neutron activation analysis	2
1.3	0.17	Neutron activation analysis	3
1.3	0.11	Spectrographic	4
	0.105–0.110	Flameless atomic absorption spectroscopy	5
1.3a	0.13a		19
1.24b	0.110b		20
1.09 ± 0.01	0.110 ± 0.005	Spectrofluorimetric	Present method

a

Values given by Fleischer.

b

Average value given by Flanagan. fluorescence intensity of the benzene-extracted rhodamine B chlorothallate is measured. The limit of determination is approximately 0.01 p.p.m. for a 1.0-g sample. The thallium contents of U.S. Geological Survey standard rocks G-1 and W-1 were found to be 1.09 ± 0.01 and 0.110 ± 0.005 p.p.m., respectively.

     

Spectrofluorimetric determination of thallium in silicate rocks with rhodamine b in the presence of aluminum chloride

A sensitive spectrofluorimetric procedure with rhodamine B in the presence of aluminum chloride is given for determining submicrogram and microgram quantities of thallium in silicate rocks. Samples are decomposed with a mixture of hydrofluoric and nitric acids and then treated with hydrochloric acid. Thallium is extracted as its dithizonate with chloroform from an alkaline medium containing ascorbate, citrate, and cyanide and then back-extracted with dilute nitric acid. After destruction of the organic matter and treatment with bromine, hydrochloric acid, aluminum chloride, and rhodamine B, the

T001. Determination of thallium in U.S. Geological Survey standard rocks by different laboratories

Electrical conduction and diffusion studies in NH4H2PO4 and KH2PO4 single crystals

Electrical conduction (dc) studies are made with pure and cobalt(II)-doped single crystals of NH₄H₂PO₄ and KH₂PO₄. The effect of the dopant concentration on the enthalpy for the migration of protons and the enthalpy for the rotation of the H₂PO₄ group have been studied. It is suggested that proton migration occurs through a synchronous phosphate rotation mechanism. Tritium diffusion studies in KDP and ³²PO₄ diffusion in ADP crystals have been made. The mechanisms for the conduction and diffusion processes are found to be different in nature. The distribution coefficients of Co(II) dopant in ADP (2.92 × 10^?3) and KDP (1.14 × 10^?3) are calculated. The following enthalpy values are obtained.

     

6.

Thermochemical properties of benzoic acid derivatives XI. Vapour pressures and enthalpies of sublimation and formation of the six dimethylbenzoic acids     

M. Colomina  P. Jimenez  M.V. Roux  C. Turrion 《The Journal of chemical thermodynamics》1984,16(12):1121-1127

The energies of combustion of 3,4- and 3,5-dimethylbenzoic acids have been revised by combustion calorimetry. Vapour pressures of very pure samples of the six dimethylbenzoic acids have been determined over a range of temperatures near 298 K by the Knudsen-effusion technique. From the experimental results and our previously published thermochemical quantities the following results for the six C₆H₃(CH₃)₂CO₂H isomers at 298.15 K have been derived.

	KDP (eV)	ADP (eV)
Enthalpy for the migration of protons	0.01 ± 0.01	0.15 ± 0.02
Enthalpy for the rotation of phosphate group	0.71 ± 0.01	0.66 ± 0.01
Enthalpy for T-diffusion	0.14 ± 0.01	—
Enthalpy for 32PO4 diffusion	—	0.24 ± 0.01

     

7.

Sur la thermogravimétrie des précipités analytiques : Dosage du mercure     

Clément Duval  Nguyen Dat Xuong 《Analytica chimica acta》1951

With the help of the CHEVENARD thermobalance, the authors have traced the pyrolysis curves of the precipitates which are used for the gravimetric determination of mercury. The methods in which a period?ate, a molybdate, a vanadate, cupferron, and 2-chloro-7-methoxy-5-thiolacridine are used, have been rejected. Only four methods out of the 21 proposed for the precipitation of metallic mercury have been considered. The dissociation of mercuric nitrate has no interest from the analytical

Isomer		$\text{Δ}{}_{\mathrm{<mtext>f</mtext>}}\text{H}{}_{\mathrm{m}}{}^{\mathrm{o}}\text{(cr)}$	$\text{Δ}{}_{\mathrm{<mtext>sub</mtext>}}\text{H}{}_{\mathrm{m}}{}^{\mathrm{o}}$	$\text{Δ}{}_{\mathrm{<mtext>f</mtext>}}\text{H}{}_{\mathrm{m}}{}^{\mathrm{o}}\text{(g)}$
	kJ·mol?1	kJ·mol?1	kJ·mol?1
2,6-	?440.7 ± 1.7	99.1 ± 0.2	?341.6 ± 1.7
2,3-	?450.4 ± 1.7	104.6 ± 0.4	?345.8 ± 1.7
2,5-	?456.1 ± 1.6	105.0 ± 0.6	?351.1 ± 1.7
2,4-	?458.5 ± 1.7	103.5 ± 0.3	?355.0 ± 1.7
3,4-	?468.8 ± 1.9	106.4 ± 0.3	?362.4 ± 1.9
3,5-	?466.8 ± 1.7	102.3 ± 0.3	?364.5 ± 1.7

     

8.

Triene electrocyclizations: Some structure reactivity relations     

E.N. Marvell  G. Caple  C. Delphey  J. Platt  N. Polston  J. Tashiro 《Tetrahedron》1973,29(23):3797-3806

Two stereoselective routes for the synthesis of trienes having a central cis double bond have been devised. These were employed for the synthesis of (Z)-1-(cyclohexen-1-yl)-1,3-butadiene (1), (Z,E)-1-(cyclohexen-1-yl)-1,3-pentadiene (2), (Z,Z)-1-(cyclohexen-1-yl)-1,3-pentadiene (3), 1,2-divinyleyclohexene (4), (E,Z)-1-phenyl-1,3,5-hexatriene (5), (Z,Z)-1-phenyl-1,3,5-hexatriene (6) and (E,Z)-1-(p-chlorophenyl)-1,3,5-hexatriene (7). Rates of the thermal electrocyclization and activation parameters were measured for these in inert solvents. The results are tabulated below.

Réactif précipitant	Forme de pesée	Limites de température
Electrolyse	Hg	<70°
Zinc + Iodure de potassium	Hg	<72°
Hydrazine	Hg	<55°
Acide hypophosphoreux	Hg	<71°
Acide nitrique	HgO	100°–200°
Acide chlorhydrique	Cl2Hg2	<130°
*Iodure de potassium	I2Hg	45°–88°
*Iodate de potassium	(IO3)2Hg2	<175°
Periodate de potassium	(IO3)2Hg2	<175°
Sulfure d'ammonium	SHg	<109°
*Thiosulfate de sodium	SHg	75–220°
Arséniate disodique	(AsO4)2Hg3	45–418°
*Thiocyanate de cobalt	[Hg(SCN)4]Co	50–200°
Thiocyanate de zinc	[Hg(SCN)4]Zn	<270°
*Chromate de potassium	CrO4Hg2	52–256°
Chromate de potassium ammoniacal	CrO4Hg2	52–256°
*Bichromate d 'ammonium + Pyridine	Cr2O7[Hg(C5H5N)2]	56–66°
*Sel de Reinecke	[Cr(CNS)4(NH3)2]2Hg	77–158°
Molybdate alcalin	[Cr(CNS)4(NH3)2]2Hg	77–158°
Tungstate alcalin	WO3	>880°
Vanadate alcalin	WO3	>880°
Iodure de cadmium ammoniacal	(HgI3)2[Cd(NH3)4]	<69°
Iodure de potassium + Sulfate de cuivre + Ethylène diamine	[HgI4][Cu En2]	à 20°
*Iodure de potassium + Sulfate de cuivre + Propylène diamine	[HgI4][Cu Pn2]	<157°
Acide oxalique	C2O4Hg2	<100°
Anthranilate de sodium	(C6H6O2N)2Hg	<113°
Pyridine	Cl2Hg(C5H5N)	<113°
Dithiane	Cl2Hg.C4H8S2	<97°
*Chlorure de cuivre-biguanide + iodure de potassium	[HgI4][Cu(C2N5H7)2]	60–175°
Cupferron	[HgI4][Cu(C2N5H7)2]	60–175°
*Thionalide	(C12H10ONS)2Hg	90–169°
Chloro-2 méthoxy-7 thiol-5 acridine	(C12H10ONS)2Hg	90–169°

     

9.

Performance of a new automatic carbon dioxide coulometer     

Edward W. D. Huffman  jr. 《Microchemical Journal》1977,22(4):567-573

The Coulometrics Inc. CO₂ coulometer has been shown to be an accurate and reliable CO₂ measuring device. The coulometric efficiency is essentially 100%. This means that the method can be considered as a standard reference method for CO₂. As with a CO₂ absorption tube, certain potential interferences must be considered, however, the removal of these interferences is well documented in the literature.The CO₂ coulometer has found a variety of applications in the author's

3. effect of flow rate on absorption of CO₂ by coulometer

Compound	k1 x 105	(sec?1)	Temp (°C)	ΔH3	ΔS3
1	12·8	132	29	?6
2	12·5	132	29	?1
3	2·6	173	34	?5
4	3·86	125	25	?15
5	16·0	145	28	?8
6	3·0	195
7	15·0	145	25	?18(?)

     

10.

Methodology for high-flux absolute multielement neutron activation analysis — environmental baselines by analysis of tree rings     

Enzo Ricci 《Analytica chimica acta》1975

Multielement determinations by high-flux absolute n.a.a. require careful methodology to avoid systematic error. The ORNL high-flux facility with a thermal flux of 5 ·10¹⁴ cm^-2 s^-1 and a thermal-to-resonance flux ratio of

T004. Analysis of Knoxville tree-core samples^a

CaCO3 (mg)	C (mg)	Flow rate (cm3/min)	C found (mg)	C (%)
27.989	3.359	100	3.3669	12.03
28.604	3.432	200	3.4343	12.00
29.259	3.511	300	3.5149	12.01
33.808	4.057	400	4.0381	11.94
5.629	0.675	500	0.6760	12.01
10.311	1.237	500	1.2337	11.96
15.647	1.878	500	1.8706	11.95
35.214	4.226	500	4.1982	11.92
40.733	4.888	500	4.8212	11.84
59.678	7.161	500	7.0263	11.77
30.386	3.646	780	3.5941	11.83
29.781	3.574	780	3.5361	11.87
28.113	3.374	1150	3.2534	11.57

Element	Increment no.20 (1832–1838)	Increment no.8 (1932–1838)	Increment no.3 (1858–1863)	Increment no.1 (1868–1872)
					Core Number	Core Number	Core Number	Core Number
	1	3	1	3	1	3	1	3
Na	12.9(1.1)	2.67(3.3)	33.8(1.0)	11.2(1.6)	15.6(1.5)	31.4(1.2)	22.4(0.93)	9.9(1.8)
Mg	c	c	160(12)b	80(27)b	100(21)b	100(30)b	c	c
Al	15.2(5.4)	5.6(6.1)	12.5(3.8)	11.0(4.4)	7.8(6.6)	8.4(7.4)	6.5(14)	6.6(6.2)
Cl	15.4(9.1)	ND	66(5.4)	ND	ND	55(6.1)	26(5.5)	22(5.1)
K	205(2.6)	223(3.3)	493(1.8)b	457(1.9)b	478(1.9)b	439(2.1)b	449(1.8)	570(1.7)
Ca	1600(11)	ND	ND	ND	ND	ND	ND	ND
Cr	ND	ND	NDb	NDb	0.3(>30)b	0.6(>30)b	0.6(>30)b	ND
Mn	109(0.30)	107(0.23)	64.1(042)	108(0.32)	46.7(051)	66.8(0.44)	38.9(0.39)	45.0(0.34)
Fe	ND	ND	ND	ND	ND	19(19)	25(18)	ND
Co	ND	0.02(>30)	ND	ND	ND	ND	0.30(>30)	ND
Zn	7.2(7)	7.4(4.2)	13.0(2.4)	9.2(3.3)	5.6(4.0)	4.5(4.7)	ND	2.4(8.8)
Br	0.10(20)	ND	0.07(12)	ND	0.024(13)	ND	0.04(>30)	ND
Rb	ND	ND	0.9(13)	0.8(18)	0.8(15)	0.7(17)	ND	1.1(18)
Ag	ND	ND	1.06(3.0)	15.3(0.71)	0.15(15)	0.69(4.8)	0.11(28)	ND
Ba	11(7.3)	10(13)	3.2(16)	ND	3.0(15)	2.9(18)	ND	3(32)
W	ND	ND	ND	ND	ND	ND	0.06(29)	ND

a

Results in p.p.m followed by (per cent counting statistical error).

b

Computer forced result.Also V,Se,Sr,Sb,Cs and au (forced) were not detected.

c

Element possibly present but missed by peak-finding routine.7 35–45, was used in developing an instrumental absolute multielement method. The detector was calibrated for absolute counting with two independent sets of radioactivity standards for four detector- -source distances; the absolute activities of the standards were reproducible within accuracies of 9%. Five sources of systematic error were investigated: (a) correction for counting of cylindrical sources for 26 γ-ray energies reached 14–17% for photon energies below 500 keV; (b) flux variation during bombardment and within the irradiation capsule volume was not significant; (c) samples were sufficiently stable during high-flux bombardment; (d) multi-element impurities in accessory materials (polyethylene and “Nucleopore” filters) were not significant; (e) correction for sample activation during rabbit transfer was necessary for short bombardments, e.g., 8.6 % for 6 s and 19.6 % for 4 s. This methodology resulted in accuracies of 10–15 % for most elements, as determined by analysis of N.B.S. orchard leaves and coal and of Bowen's kale standards. The method was applied to a preliminary chronological study of environmental baselines and contamination levels, based on tree ring samples, covering a period of 100 years.

     

Thermochemical properties of benzoic acid derivatives XI. Vapour pressures and enthalpies of sublimation and formation of the six dimethylbenzoic acids

The energies of combustion of 3,4- and 3,5-dimethylbenzoic acids have been revised by combustion calorimetry. Vapour pressures of very pure samples of the six dimethylbenzoic acids have been determined over a range of temperatures near 298 K by the Knudsen-effusion technique. From the experimental results and our previously published thermochemical quantities the following results for the six C₆H₃(CH₃)₂CO₂H isomers at 298.15 K have been derived.

Sur la thermogravimétrie des précipités analytiques : Dosage du mercure

With the help of the CHEVENARD thermobalance, the authors have traced the pyrolysis curves of the precipitates which are used for the gravimetric determination of mercury. The methods in which a period?ate, a molybdate, a vanadate, cupferron, and 2-chloro-7-methoxy-5-thiolacridine are used, have been rejected. Only four methods out of the 21 proposed for the precipitation of metallic mercury have been considered. The dissociation of mercuric nitrate has no interest from the analytical

Triene electrocyclizations: Some structure reactivity relations

Two stereoselective routes for the synthesis of trienes having a central cis double bond have been devised. These were employed for the synthesis of (Z)-1-(cyclohexen-1-yl)-1,3-butadiene (1), (Z,E)-1-(cyclohexen-1-yl)-1,3-pentadiene (2), (Z,Z)-1-(cyclohexen-1-yl)-1,3-pentadiene (3), 1,2-divinyleyclohexene (4), (E,Z)-1-phenyl-1,3,5-hexatriene (5), (Z,Z)-1-phenyl-1,3,5-hexatriene (6) and (E,Z)-1-(p-chlorophenyl)-1,3,5-hexatriene (7). Rates of the thermal electrocyclization and activation parameters were measured for these in inert solvents. The results are tabulated below.

Performance of a new automatic carbon dioxide coulometer

The Coulometrics Inc. CO₂ coulometer has been shown to be an accurate and reliable CO₂ measuring device. The coulometric efficiency is essentially 100%. This means that the method can be considered as a standard reference method for CO₂. As with a CO₂ absorption tube, certain potential interferences must be considered, however, the removal of these interferences is well documented in the literature.The CO₂ coulometer has found a variety of applications in the author's

3. effect of flow rate on absorption of CO₂ by coulometer

Methodology for high-flux absolute multielement neutron activation analysis — environmental baselines by analysis of tree rings

Multielement determinations by high-flux absolute n.a.a. require careful methodology to avoid systematic error. The ORNL high-flux facility with a thermal flux of 5 ·10¹⁴ cm^-2 s^-1 and a thermal-to-resonance flux ratio of

T004. Analysis of Knoxville tree-core samples^a

The mechanism and kinetics of energy transfer processes in the Xe–CCl4–M (M=CH4, C2H2, C2H4, C2H6 C3H6 and C3H8) mixtures irradiated by xenon resonance light

The mechanism and kinetics of energy transfer from Xe(6s[3/2]₁) resonance state (E=8.44 eV) to selected hydrocarbon molecules have been investigated by XeCl(B–X) (λ_max=308 nm) fluorescence intensity measurements at stationary conditions in Xe–CCl₄–M systems. Steady-state analysis of the fluorescence intensity dependence on the xenon and M pressure at constant CCl₄ concentration shows that these process occur in the two- and three-body reactions: Xe(6s[3/2]₁⁰)+M→products, Xe(6s[3/2]₁⁰+M+Xe→products. The two- and three-body rate constants for these reactions have been found (see Table 1Table 1. Experimental parameters of Eq. (8)found by least square method in Xe–CCl₄–C₂H₂ and Xe–CCl₄–C₂H₄ systems for chosen xenon pressures in the range 25–150 Torr. Linear correlation coefficients (R) are also shown     

12.

Solvent extraction studies of cobalt in aqueous thiocyanate solutions using Aliquat-336     

Curtis McDonald  Carina M. Alfaro-Franco 《Microchemical Journal》1984,30(2):194-200

Cobalt ions in aqueous thiocyanate solution react with Aliquat-336-xylene solution to form anion-association complex which is easily extracted into the organic phase. A typical extraction procedure involves extracting a solution which is 10 ppm in cobalt and 0.06 M,

5. Stripping of Cobalt from 2% Aliquat-336-Xylene Solutions

Solvent extraction studies of cobalt in aqueous thiocyanate solutions using Aliquat-336

Cobalt ions in aqueous thiocyanate solution react with Aliquat-336-xylene solution to form anion-association complex which is easily extracted into the organic phase. A typical extraction procedure involves extracting a solution which is 10 ppm in cobalt and 0.06 M,

5. Stripping of Cobalt from 2% Aliquat-336-Xylene Solutions

Spectroscopic investigations of hydrogen bonding interactions in the gas phase: Part VI. A microwave spectroscopie determination of geometry for the heterodimer (CH2)3O⋯HF formed between oxetane and hydrogen fluoride: hydrogen bonding as a probe for lone pairs

The hydrogen-bonded heterodimer formed between oxetane and hydrogen fluoride is identified and characterised by means of its IR and microwave spectra. The following rotational constants (MHz) and centrifugal distortion constants (kHz) have been derived:

Sur la thermogravimétrie des précipités analytiques: Dosage du chrome

By means of the CHEVENARD thermobalance, the precipitates used for the determination of chromium have been investigated and the following limits of temperature established:

The oxidation of organic substances with compounds of trivalent manganese: XXI. The oxidation of glycoaldehyde with hexaquomanganese(III) ions in a noncomplexing perchloric acid medium

The oxidation of glycolaldehyde with hexaquomanganese(III) ions in a noncomplexing perchloric acid medium was studied. The optimum conditions have been found for analytical use of the reaction. The recommended procedure is based on the oxidation of the test substance with the oxidant in the absence of atmospheric oxygen and back-titration of the unconsumed reagent with ferrous sulfate.

2. Accuracy and Reproducibility of the Determination of Glycolaldehyde with Hexaquomanganese(III) Ions in a Noncomplexing Perchloric Acid Medium

Interelement effects in x-ray fluorescence spectrometry. Analysis of the iron-copper-sulfur system

The Rasberry-Heinrich and Claisse-Quintin equations give a good interpretation of the theoretical intensity-concentration relationship in x-ray fluorescence spectrometry. The influence constants (A_x, A_x) of these equations can be calculated. Trace element and structural effects require an empirical correction, which is important in iron-copper-sulfur systems (reverberatory mattes and copper concentrates). The empirical correction in combination with either of the above equations can furnish very good quantitative results from fluorescence intensity measurements.

t005. Analysis of some copper intermediates^a

Specimen	RFe	RCu	RS	%Fe			%Cu			%S
				W	RH	CQ	W	RH	Cl	W	RH	Cl
Reverberatory matte
5-268	0.4717	0.2710	0.1093	35.6	35.52	35.52	32.83	32.82	31.79	26.64	26.62	26.66
5-331	0.4394	0.3042	0.1059	32.0	32.11	32.12	37.17	37.33	37.29	26.42	26.35	26.43
5-336	0.4210	0.3131	0.1126	30.6	30.48	30.45	37.52	37.57	37.65	27.02	26.97	27.03
5-339	0.4295	0.3062	0.1042	31.4	31.29	31.34	37.23	37.13	37.26	26.16	26.04	26.19
5-344	0.4395	0.3094	0.1052	31.8	32.01	31.97	38.42	38.33	38.17	26.09	26.35	26.43
Average deviation (±)		0.13	0.12		0.08	0.11		0.10	0.03
k1					0.899	0.953		1.175	1.133		0.274	0.245
k2					-1.137	-4.146		-20.73	-20.16		14.09	15.26
Concentrate I
2-18	0.3111	0.2809	0.1410	27.7	27.60	27.60	25.79	25.50	25.51	38.83	38.83	38.82
2-20	0.3226	0.2598	0.1445	28.2	28.42	28.42	23.23	23.58	23.57	38.62	38.88	38.88
2-22	0.3335	0.2303	0.1495	29.4	29 31	29.31	20.53	20.62	20.61	39.14	38.90	38.90
3-4	0.3376	0.2007	0.1498	30.2	29.87	29.87	17.82	17.46	17.46	38.59	38.59	38.58
3-5	0.3396	0.1976	0.1515	29.7	30.01	30.00	16.92	17.14	17.14	38.65	38.65	38.65
Average deviation (±)					0.21	0.21		0.26	0.26		0.10	0.11
k1					0.590	0.616		0.783	0.776		0.158	0.162
k2					12.11	10.34		-4.82	-6.60		31.18	30.60
Concentrate II
7-1	0.3821	0.2403	0.1409	28.4	28.29	28.34	27.13	27.38	27.37	32.48	32.54	32.53
7-2	0.3724	0.2406	0.1414	27.9	27.82	27.80	27.33	27.10	27.13	32.32	32.44	32.45
7-3	0.3804	0.2368	0.1414	28.2	28.24	28.29	26.88	26.91	26.87	32.78	32.49	32.49
7-4	0.3825	0.2502	0.1459	28.0	28.20	28.17	28.50	28.45	28.49	32.84	33.08	33.09
7-5	0.3932	0.2559	0.1496	28.7	28.65	28.62	29.41	29.41	29.39	33.74	33.62	33.61
Average deviation ( ± )					0.10	0.10		0.11	0.10		0.17	0.17
k1					0.525	0.649		0.778	0.877		0.216	0.224
k2					10.74	5.740		-0.66	-6.19		21.76	20.87

a

Most of the iron and copper was present as FeS and Cu₂S, respectively; W is the “wet” method. Concentrates I and II contained 6.0% SiO₂-2.2% Al₂O₃ and 4.6% SiO₂-1.8% Al₂O₃, respectively (average values).

     

Sur la thermogravimétrie des précipités analytiques: Dosage de l'uranium

A study has been made of the gravimetric methods for the determination of 4- and 6-valent uranium and two new forms of weighing are suggested, as oxalate and anhydrous oxmate. The following table summarizes the temperature limits, determined by means of the Chevenard thermobalance, for various precipitates:

     

18.

Analysis of nitrate-perchlorate mixtures by difference spectrophotometry     

Salah Shahine  Soad Khamis 《Microchemical Journal》1979,24(4):439-443

Nitron and tetraphenylarsonium chloride react with a cobaltous salt in the presence of thiocyanate to form blue ion-association complexes, which can be extracted with organic solvents. This fact has been made the basis for the analysis of mixtures of nitrate and perchlorate by difference spectrophotometry. An aliquot of the sample solution is treated with a known excess of tetraphenylarsonium chloride to precipitate perchlorate only. After separating off the precipitate, the excess of reagent is determined in the supernatant liquid as tetraphenylarsonium cobaltothiocyanate and the perchlorate content can be found from a calibration curve. Another aliquot is treated with an excess of nitron to precipitate both anions; the excess of nitron is then determined as nitron

2. Analysis of Nitrate-Perchlorate Mixtures

Precipitating reagent	Form in which weighed	Temperature limits
Ammonium hydroxide	UO3	480–610°
Ammonium hydroxide	U3O8	745–946°
Ammoniac (gas)	U3O8	675–946°
Pyridine	U3O8	745–946°
Ammonium benzoate	U3O8	691–946°
Hexamethylenetetramine	U3O8	745–946°
Tannin	U3O8	570–878°
Hydrogen peroxide	U3O8	811–946°
Hydrofluoric acid	U3O8	811–946°
Ammonium sulphate	U3O8	850–946°
Disodium phosphate	U2P2O11	673–946°
Oxalic acid	U(C2O4)2	100–180°
Oxalic acid	U3O8	700–946°
Cupferron	U3O8	800–946°
β-Isatoxime	U3O8	408–946°
8-Hydroxyquinoline	HUO2(C9H6ON)3	< I57°
8-Hydroxyquinoline	UO2(C9H6ON)2	252–346°
Quinaldinic acid	U3O8	610–946°

     

19.

Amperometric titration of copper in brass     

Theodore R. Williams  Frederick G. Burton 《Analytica chimica acta》1962

A direct amperometric titration of copper is described; o-(p-tolylsulfonamido) aniline serves as titrant. The optimum conditions are discussed and the method is applied to the analysis of copper in brass alloys.

t001. IV. Analysis of various samples in which copper was determined (Values given as percentages)

Perchlorate			Nitrate
Taken (μg)	Found (μg)	Error (%)	Taken (μg)	Found (μg)	Error (%)
400	404	+ 1.00	248	250	+0.81
400	400	0.00	496	492	?0.81
400	400	0.00	992	992	0.00
800	796	?0.50	248	248	0.00
600	602	+0.33	248	245	?1.21
800	792	?1.25	496	498	+0.40

     

20.

Sur la thermogravimt́rie des prćipitś analytiques: Dosage de l'indium     

Thérése Dupuis  Clément Duval 《Analytica chimica acta》1949

The authors discuss several aspects of the chemistry of indium, giving evidence for a hydrate 2ln₂O₃.H₂O and studying in detail the behaviour of indium sulphide heated in air. Compared with that of gallium, the oxinate is particularly stable.Compounds used for the gravimetric determination of indium should be heated to the following temperatures in order to give correct results:

Constituents	Thorn Smith # 30	Thorn Smith # 54	NBS # 37E	NBS # 63C
Cu present	59.30	84.04	69.61	80.48
Zn	37.81	1.452	27.85	0.093
Pb	0.1	8.590	1.00	9.35
Sn	Trace	5.737	1.00	9.03
Sb				0.52
Ni	Trace		0.53	0.32
P				0.145
S				0.060
As				0.023
Fe	1.22		0.004	0.0013
Al	1.15
Mn	0.35
Cu found	59.09	83.64	69.68a	80.54a	aAverage of 3 determinations.

     

Hydroxide by ammonia	345°
Hydroxide by hexamethylene tetramine	546°
Hydroxide by cyanate	475°
Sulphide	94–221°, 320–544°, 690°
Phosphate	477°
Luteocobaltic indichloride	100–105°
Oxinate	100–285°
Diethyldithiocarbamate	100–210°

Analysis of nitrate-perchlorate mixtures by difference spectrophotometry

Nitron and tetraphenylarsonium chloride react with a cobaltous salt in the presence of thiocyanate to form blue ion-association complexes, which can be extracted with organic solvents. This fact has been made the basis for the analysis of mixtures of nitrate and perchlorate by difference spectrophotometry. An aliquot of the sample solution is treated with a known excess of tetraphenylarsonium chloride to precipitate perchlorate only. After separating off the precipitate, the excess of reagent is determined in the supernatant liquid as tetraphenylarsonium cobaltothiocyanate and the perchlorate content can be found from a calibration curve. Another aliquot is treated with an excess of nitron to precipitate both anions; the excess of nitron is then determined as nitron

2. Analysis of Nitrate-Perchlorate Mixtures

Amperometric titration of copper in brass

A direct amperometric titration of copper is described; o-(p-tolylsulfonamido) aniline serves as titrant. The optimum conditions are discussed and the method is applied to the analysis of copper in brass alloys.

t001. IV. Analysis of various samples in which copper was determined (Values given as percentages)

Sur la thermogravimt́rie des prćipitś analytiques: Dosage de l'indium

The authors discuss several aspects of the chemistry of indium, giving evidence for a hydrate 2ln₂O₃.H₂O and studying in detail the behaviour of indium sulphide heated in air. Compared with that of gallium, the oxinate is particularly stable.Compounds used for the gravimetric determination of indium should be heated to the following temperatures in order to give correct results: